Resistance to Sweat
The protective performance of a sun protection product is assessed through its SPF, UPF and substantivity. A product’s substantivity is defined as its ability to bind to the skin and resist removal. In the case of suncare products, this generally involves assessing resistance to water, sand or rubbing against fabrics. However, unlike the elements involved in exposure above the sun protection film, sweat is released below the sun protection film to ensure thermoregulation of the body, during physical activity or in high temperatures.
Under these conditions, customers are usually also exposed to the sun, so sun protection must be intact. In order to determine and substantiate this claim of product efficacy, WENEOS has developed an exclusive in vitro method which requires the measurement of a sun protection factor (SPF) before and/or after exposure to sweat.
sweat resistance
days for an in vitro study with a final report
solar studies carried out
%
compliance with solar standards
CLAIM
We can assess the sun protection of your products in full compliance with official methods, or claim the properties of your products through exclusive tests developed by WENEOS.
Sweat resistance in vitro
WENEOS has developed a new perspiration simulator to assess the in vitro perspiration resistance of a sunscreen product.
Thus, using a spectrophotometric in vitro method, products can be exposed to an artificial sweat solution under a set of specific conditions (flow rate, exposure time, orientation, etc.). Next, the percentage of perspiration resistance is obtained by calculating the ratio of the sun protection factor (SPF) before and after exposure for each condition. Finally, to be declared perspiration-resistant, this percentage must be greater than 50% for both conditions tested.
(ref. HeSWEAT)
Published method: In progress
Control
To optimize your suncare products or check their quality, we offer you exclusive tests developed by WENEOS.
Comparison of in vitro signal absorbance measurements with resistance (batch, aging, etc.)
The statistical comparison method makes it possible to compare two sun protection products in terms of ageing, batch, benchmark, etc. When checking the absorbance spectrum between a reference and a test product using an in vitro method, two important rules must be observed. First of all, compare the two products at the same time and under the same conditions, to limit measurement variability. Secondly, a three-step verification based on absorbance values, including comparison of curve shape, variability and intensity.
In this method, a specific step for comparing the resistance of the two products can be added, such as water resistance, friction resistance, etc.
(ref. HeCOMP-2)
Published method : *In vitro comparison - A new accessible and reliable statistical method to compare the global UV protection properties of cosmetics - Lutz and S. Miksa, H&PC Sun Care, July/August 2013 | *Sunscreen products: Some practical applications for a new comparison test method to help Development and ensure Quality Controls - D. Lutz, S. Miksa and C. Guy, H&PC Today, November/December 2014
Discover the analyses additionalfor all-round sun protection
UV protection
- SPF – UVB
- UVAPF – UVA
- UVA:UVB ratio
- Photostability
- Absorbance spectrum
Beyond UV
- Ultra-Long UVA
- Blue Light
- Visible
- Infrared
- Full Spectrum
- UVC
Resistance
- Water resistance
- Sweat resistance
- Sand resistance
- Rub resistance
- Wet Skin Application
- Extreme conditions
- Persistence | Long-lasting
- Immediate protection